SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '960bd1186f9a6489cc73cdddc0b1681172ec81d7036b01ccea6338c072fd4c02' 
  AND token = 'VpXz8SEPEQeeqH/b5JVfvcOxw+p8sBwk0UTpcQqHOyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}